JP4957819B2 - IPv4-IPv6 multicast communication method and apparatus - Google Patents

Description

  The present invention relates to an IPv4-IPv6 multicast communication method and an IPv4-IPv6 multicast communication apparatus in a communication network system. More specifically, the present invention relates to a multicast communication method between an IPv4 terminal using IPv4 (IPv4: Internet Protocol version 4) as a communication protocol and an IPv6 terminal using IPv6 (IPv6: Internet Protocol version 6) as a communication protocol. And device.

  As a method for realizing communication between an IPv4 terminal and an IPv6 terminal, a technique described in Japanese Patent Application Laid-Open No. 11-55319 is given as an example. The technology creates an IP address conversion table for managing the correspondence between IPv4 addresses and IPv6 addresses by using a DNS (Domain Name System) protocol extension technology for a device in the middle of a communication path, and based on the IP address conversion table. By performing the IPv4 header-IPv6 header conversion, communication between the IPv4 terminal and the IPv6 terminal is enabled.

JP-A-11-55319

  The above prior art enables IP unicast communication between an IPv4 terminal and an IPv6 terminal. However, the above prior art does not consider IP multicast communication between an IPv4 terminal and an IPv6 terminal. An object of the present invention is to provide a method and apparatus for performing IP multicast communication between an IPv4 terminal and an IPv6 terminal.

  It is another object of the present invention to provide a method and apparatus for receiving an IP multicast packet transmitted from an IPv4 terminal at the IPv6 terminal.

  It is another object of the present invention to provide a method and apparatus for receiving an IP multicast packet transmitted from an IPv6 terminal at the IPv4 terminal.

  In order to achieve the above object, according to a first aspect, the present invention provides a method for performing IP multicast communication between an IPv4 terminal of an IPv4 network and an IPv6 terminal of an IPv6 network in a communication network system including an IPv4 network and an IPv6 network. And (a) a translation device connected to both the IPv4 network and the IPv6 network joins a group for an IPv4 multicast packet broadcast (transmitted) by the IPv4 terminal in accordance with an instruction from the manager of the translation device. , In response to the administrator's instruction, select one of the IPv6 multicast addresses stored in advance in the translation device and associate it with the IPv4 address of the group; (b) the translation device IPv4 terminal broadcast (transmit) When an IPv4 multicast packet is received, the IPv4 end address included in the IPv4 multicast packet is converted into an IPv6 end address using an IPv6 address corresponding to the IPv4 end address, and is stored in the conversion device in advance according to an instruction from the administrator. The IPv6 multicast packet is selected from the IPv4 multicast packet by the IP header conversion for converting the IPv4 start point address included in the IPv4 multicast packet to the IPv6 start point address using the selected IPv6 unicast address. (C) providing an IPv4-IPv6 multicast communication method characterized in that the IPv6 terminal receives the IPv6 multicast packet; That.

  In the IPv4-IPv6 multicast communication method according to the first aspect, an IP multicast packet broadcast (transmitted) by an IPv4 terminal of an IPv4 network can be received by the IPv6 terminal of the IPv6 network. At this time, all the processing performed by the conversion device between the IPv4 terminal and the IPv6 terminal can be realized by a technique described in RFC (RFC: Request for Comments), and new processing is performed on the IPv4 terminal and the IPv6 terminal. It can be realized without modification.

  In a second aspect, the present invention relates to a method for performing IP multicast communication between an IPv4 terminal of an IPv4 network and an IPv6 terminal of an IPv6 network in a communication network system including an IPv4 network and an IPv6 network, and (a) an IPv4 network And a translation device connected to both the IPv6 network joins a group for an IPv6 multicast packet broadcast (transmitted) by the IPv6 terminal according to an instruction from the administrator of the translation device, and in advance according to the instruction from the administrator Select one of the IPv4 multicast addresses held in the conversion device and associate it with the IPv6 address of the group. (B) The conversion device broadcasts (sends) an IPv6 multicast path broadcasted by the IPv6 terminal. The IPv6 end point address included in the IPv6 multicast packet is converted into an IPv4 end point address using the corresponding IPv4 address, and is stored in advance in the conversion device according to the instructions of the administrator. One of the IPv4 unicast addresses is selected, and an IPv4 multicast packet is created from the IPv6 multicast packet by IP header conversion for converting the IPv6 start address included in the IPv6 multicast packet to the IPv4 start address using the selected IPv4 unicast address. And (c) the IPv4 terminal receives the IPv4 multicast packet, and provides an IPv4-IPv6 multicast communication method.

  In the IPv4-IPv6 multicast communication method according to the second aspect, the IP multicast packet broadcast (transmitted) by the IPv6 terminal of the IPv6 network can be received by the IPv4 terminal of the IPv4 network. At this time, all the processing performed by the conversion device between the IPv4 terminal and the IPv6 terminal can be realized by the technology described in RFC, and can be realized without adding new modifications to the IPv4 terminal and the IPv6 terminal. be able to.

  In a third aspect, the present invention provides (a) an IP transmission / reception means for transmitting / receiving an IPv4 packet to / from an IPv4 network and an IPv6 packet to / from an IPv6 network, and (b) an IPv4 unicast address used for IP header conversion. , An IPv4 multicast address, an IPv6 unicast address, and an IP address holding means for conversion that holds the IPv6 multicast address, and (c) an IPv4 end point address of the IPv4 multicast packet broadcast (transmitted) by the IPv4 terminal of the IPv4 network and the conversion IPv6 multicast address obtained from the IP address holding means (obtained if not yet), IPv4 start address of the IPv4 multicast packet and the conversion IP address holding means. IPv6 unicast address (obtained if not yet), IPv6 end point address of IPv6 multicast packet broadcast (transmitted) by the IPv6 terminal of the IPv6 network, and IPv4 multicast address obtained from the IP address holding means for conversion (uncompleted) IP address conversion information holding that holds the IPv6 start point address of the IPv6 multicast packet and the IPv4 unicast address acquired from the IP address holding unit for translation (obtained if not already acquired) in association with each other And (d) IPv4 multicast group and IPv6 multicast group subscription management in accordance with instructions from the administrator of the apparatus, and the IPv4 address of the IPv4 multicast group to join An IPv6 address corresponding to it, or an IPv6 address of an IPv6 multicast group to join and an IPv4 address corresponding to the IPv6 address, instructing the IP address translation information holding means to register, and (e) from the IP transmitting / receiving means The IPv4 end point address of the passed IPv4 multicast packet is inquired to the IP address conversion information holding means, and converted to an IPv6 end point address using the corresponding IPv6 address, and the IPv4 start point address of the IPv4 multicast packet is converted to the IP address. The IPv4 multicast packet is obtained by the IP header conversion that inquires the address conversion information holding means and converts the IPv6 start address using the corresponding IPv6 address. An IPv6 multicast packet is created from the IP address, the IPv6 network is instructed to send to the IPv6 network, and the IPv6 end point address of the IPv6 multicast packet passed from the IP transceiver means is inquired of the IP address conversion information holding means. The IPv6 start point address of the IPv6 multicast packet is converted to an IPv4 start point address using the corresponding IPv4 address by inquiring of the IPv6 start point address of the IPv6 multicast packet while converting to the IPv4 end point address using the corresponding IPv4 address. An IP header conversion that creates an IPv4 multicast packet from the IPv6 multicast packet by IP header conversion and instructs the IP transmitting / receiving means to send it to an IPv4 network. And means to provide a conversion apparatus characterized by comprising.

  According to the conversion device of the third aspect, the IPv4-IPv6 multicast communication method of the first aspect and the second aspect can be suitably implemented. According to a fourth aspect of the present invention, in the conversion device having the above-described configuration, the IP address conversion information holding unit is not referred to for a certain period of time from among the correspondence between the held IPv4 unicast address and IPv6 unicast address. Is provided, and the IPv4 unicast address and the IPv6 unicast address that have been deleted are returned to the conversion IP address holding means.

  According to the translation device of the fourth aspect, since the unused IPv4 unicast address and IPv6 unicast address are returned to the translation IP address holding means, consumption of the IPv4 unicast address and IPv6 unicast address is suppressed. I can do it.

  In a fifth aspect, the present invention relates to the conversion apparatus configured as described above, wherein the IP multicast subscription group management means leaves the IPv4 multicast group or the IPv6 multicast group according to an instruction from an administrator of the apparatus, and leaves IPv4. The IPv4 address of the multicast group and the corresponding IPv6 address, or the IPv6 address of the leaving IPv6 multicast group and the corresponding IPv4 address are instructed to the IP address translation information holding means to delete the registration, and the IP address translation information holding means Provides a conversion apparatus characterized in that the deleted IPv4 multicast address and IPv6 multicast address are returned to the conversion IP address holding means.

  According to the conversion device of the fifth aspect, the IPv4 multicast address or the IPv6 multicast address of the leaving IP multicast group is returned to the conversion IP address holding means, so that consumption of the IPv4 multicast address or the IPv6 multicast address is suppressed. be able to.

  According to the present invention, it is possible to perform IP multicast communication between an IPv4 terminal and an IPv6 terminal.

  According to the present invention, an IPv6 terminal can receive an IP multicast packet broadcast (transmitted) from an IPv4 terminal. Further, the IPv4 terminal can receive an IP multicast packet broadcast (transmitted) from the IPv6 terminal.

It is a lineblock diagram of the conversion device concerning a 1st embodiment of the present invention. It is a block diagram of an IPv4 unicast address table. It is a block diagram of an IPv4 multicast address table. It is a block diagram of an IPv6 unicast address table. It is a block diagram of an IPv6 multicast address table. It is a block diagram of an IP address conversion table. It is a block diagram of an IPv4 multicast subscription table. It is a block diagram of an IPv6 multicast subscription table. 1 is a configuration diagram of a communication network system according to a first embodiment of the present invention. It is a flowchart in the case of receiving with an IPv6 multicast client the IP multicast packet which an IPv4 multicast server broadcasts (transmits) via the conversion apparatus which concerns on the 1st Embodiment of this invention. FIG. 11 is a flowchart continued from FIG. 10. It is a block diagram of the communication network system which concerns on embodiment different from the 1st Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. Note that the present invention is not limited thereby.

-First embodiment-
FIG. 1 is a configuration diagram of a conversion apparatus 1a according to the first embodiment of the present invention.

  The conversion device 1a is located between the IPv4 network 101 and the IPv6 network 102, and performs IP multicast communication between the IPv4 terminal and the IPv6 terminal by performing IP header conversion between the IPv4 multicast packet and the IPv6 multicast packet. Realize. The translation device 1a includes an IP transmission / reception means 2, a translation IP address holding means 3, an IP address translation information holding means 4, an IP multicast subscription group management means 5, and an IP header translation means 6.

  The IP transmission / reception unit 2 is a unit that performs transmission / reception of IPv4 packets with the IPv4 network 101 and transmission / reception of IPv6 packets with the IPv6 network 102. The IP transmission / reception means 2 is composed of, for example, an electronic device such as a CPU, an ASIC, or a RAM, and a program that is held in a storage device such as a RAM and is necessary for executing the above means.

  The translation IP address holding means 3 is means for holding an IPv4 unicast address, an IPv4 multicast address, an IPv6 unicast address, and an IPv6 multicast address used for IP header translation. The conversion IP address holding means 3 is composed of, for example, an electronic device such as a CPU, ASIC, or RAM, and a program that is held in a storage device such as a RAM and is necessary for executing the means. An IPv4 unicast address, an IPv4 multicast address, an IPv6 unicast address, and an IPv6 multicast address used for IP header translation are respectively an IPv4 unicast address table 31, an IPv4 multicast address table 32, an IPv6 unicast address table 33, and an IPv6 multicast address table. 34.

  The IP address translation information holding unit 4 includes an IPv4 end point address of an IPv4 multicast packet broadcast (transmitted) by an IPv4 terminal of the IPv4 network 101, and an IPv6 multicast address acquired from the translation IP address holding unit 3 (if not yet completed) The IPv4 start point address of the IPv4 multicast packet and the IPv6 unicast address acquired from the translation IP address holding means 3 (obtained if not already acquired), and the IPv6 terminal of the IPv6 network 102 broadcasts (transmits) The IPv6 end point address of the IPv6 multicast packet to be transmitted, the IPv4 multicast address acquired from the IP address holding means 4 for translation (obtained if not yet), and the IPv6 multicast packet IPv6 source address and the converted IP address IPv4 obtained from the holding means 4 unicast address (if not yet obtains) a means for holding in association with. The IP address conversion information holding unit 4 includes an electronic device such as a CPU, an ASIC, and a RAM, and a program that is held in a storage device such as a RAM and is necessary for executing the above unit. The IPv4 end point address of the IPv4 multicast packet and the corresponding IPv6 address, the IPv4 start point address of the IPv4 multicast packet and the corresponding IPv6 address, the IPv6 end point address of the IPv6 multicast packet and the corresponding IPv4 address, and the IPv6 multicast packet The IPv6 start point address and the corresponding IPv4 address are held in the IP address conversion table 41, respectively.

  The IP multicast subscription group management means 5 manages the subscription status of the IPv4 multicast group and the IPv6 multicast group in accordance with an instruction from the administrator of the conversion apparatus 1a, and also IPv4 addresses of the IPv4 multicast groups to be joined and corresponding IPv6 addresses. Alternatively, the IPv6 address of the joining IPv6 multicast group and the corresponding IPv4 address are instructed and registered in the IP address translation information holding means 4. The IP multicast subscription group management means 5 includes, for example, an electronic device such as a CPU, an ASIC, and a RAM, and a program that is held in a storage device such as a RAM and is necessary for executing the above means. The IPv4 address of the subscribed IPv4 multicast group is held in the IPv4 multicast join table 51, and the IPv6 address of the subscribed IPv6 multicast group is held in the IPv6 multicast join table 52.

  The IP header conversion unit 6 creates an IPv6 multicast packet from the IPv4 multicast packet passed from the IP transmission / reception unit 2 by IP header conversion, and instructs the IP transmission / reception unit 2 to send the packet to the IPv6 network 102. In the IP header conversion, the IP header conversion means 6 inquires of the IP address conversion information holding means 4 and converts the IPv4 end address of the IPv4 multicast packet into an IPv6 end address using the corresponding IPv6 address, The IPv4 start point address of the IPv4 multicast packet is converted into an IPv6 start point address using the corresponding IPv6 address. Further, the IP header converting unit 6 creates an IPv4 multicast packet from the IPv6 multicast packet passed from the IP transmitting / receiving unit 2 and instructs the IP transmitting / receiving unit 2 to send it to the IPv4 network 101. In the IP header conversion, the IP header conversion unit 6 inquires of the IP address conversion information holding unit 4 to convert the IPv6 end point address of the IPv6 multicast packet into an IPv4 end point address using the corresponding IPv4 address. The IPv6 start point address of the IPv6 multicast packet is converted into an IPv4 start point address using the corresponding IPv4 address. The IP header converting means 6 is composed of, for example, an electronic device such as a CPU, ASIC, or RAM, and a program that is held in a storage device such as a RAM and is necessary for executing the above means.

  FIG. 2 is a configuration diagram of the IPv4 unicast address table 31. In the IPv4 unicast address table 31, an IPv4 unicast address used for IP header translation is registered in advance according to an instruction from the administrator of the translation device 1a. Here, it is assumed that IPv4 addresses 133.144.93.100 to 133.144.93.200 are registered.

  FIG. 3 is a configuration diagram of the IPv4 multicast address table 32. In the IPv4 multicast address table 32, an IPv4 multicast address used for IP header translation is registered in advance according to an instruction from the administrator of the translation device 1a. Here, it is assumed that IPv4 addresses of 238.0.0.100 to 238.0.0.200 are registered.

  FIG. 4 is a configuration diagram of the IPv6 unicast address table 33. In the IPv6 unicast address table 33, IPv6 unicast addresses used for IP header translation are registered in advance in accordance with instructions from the administrator of the translation apparatus 1a. Here, it is assumed that an IPv6 address of 1 :: 100 to 1 :: 200 is registered.

  FIG. 5 is a configuration diagram of the IPv6 multicast address table 34. In the IPv6 multicast address table 34, an IPv6 multicast address used for IP header translation is registered in advance according to an instruction from the administrator of the translation apparatus 1a. Here, it is assumed that IPv6 addresses from ff1e :: 100 to ff1e :: 200 are registered.

  FIG. 6 is a configuration diagram of the IP address conversion table 41. The IP address conversion table 41 includes an IPv4 end point address of the received IPv4 multicast packet and an IPv6 address corresponding to the IPv4 end point address, an IPv4 start point address of the received IPv4 multicast packet and an IPv6 address corresponding thereto, an IPv6 end point address of the received IPv6 multicast packet and the corresponding IPv4. The address and the IPv6 start point address of the received IPv6 multicast packet and the corresponding IPv4 address are held in association with each other.

  FIG. 7 is a configuration diagram of the IPv4 multicast subscription table 51. In the IPv4 multicast subscription table 51, IPv4 addresses of IPv4 multicast groups that have joined in accordance with instructions from the administrator of the conversion device 1a are registered.

  FIG. 8 is a configuration diagram of the IPv6 multicast subscription table 52. In the IPv6 multicast subscription table 52, IPv6 addresses of IPv6 multicast groups that have joined in accordance with instructions from the administrator of the conversion apparatus 1a are registered.

  FIG. 9 is a schematic diagram of a communication network system in which the IPv4 network 101 and the IPv6 network 102 are connected via the conversion device 1a. An IPv4 multicast server 104 that broadcasts (transmits) multicast packets by IPv4 and an IPv4 multicast client 105 that receives multicast packets by IPv4 are connected to the IPv4 network 101. Similarly, an IPv6 multicast server 106 that broadcasts (transmits) multicast packets by IPv6 and an IPv6 multicast client 107 that receives multicast packets by IPv6 are connected to the IPv6 network 102.

  Here, IPv4 address 133.144.93.1 and IPv6 address 1 :: 1 are assigned to the conversion device 1a, and IPv4 address 133.144.93.2 is assigned to the IPv4 multicast server 104. Suppose that Also, IPv4 address 133.144.93.3 is assigned to IPv4 multicast client 105, IPv6 address 1 :: 2 is assigned to IPv6 multicast server 106, and IPv6 address 1 :: 3 is assigned to IPv6 multicast client 107. It shall be.

  Further, it is assumed that the IPv4 multicast server 104 broadcasts (transmits) an IPv4 multicast packet to the IPv4 network 101 using the IPv4 address 238.0.0.1. Similarly, it is assumed that the IPv6 multicast server 106 broadcasts (transmits) an IPv6 multicast packet to the IPv6 network 102 using the IPv6 address ff1e :: 1.

  In FIG. 9, the IPv4 network 101 and the IPv6 network 102 are completely separated, but the same applies when the IPv4 network 101 and the IPv6 network 102 coexist in the physically same network.

  10 and 11 are flowcharts of operations when the IPv6 multicast client 107 receives an IPv4 multicast packet broadcast (transmitted) to the IPv4 network 101 by the IPv4 address of 238.0.0.1 by the IPv4 multicast server 104. is there.

  The IPv4 multicast server 104 broadcasts (transmits) an IPv4 multicast packet to the IPv4 network 101 with an IPv4 address of 238.0.0.1 (FIG. 10).

  The administrator of the conversion device 1a converts the IPv4 multicast packet into an IPv6 multicast packet and relays it to the IPv6 network 102, so that the IP multicast subscription group management means joins the multicast group with the IPv4 address 238.0.0.1. Instruct 5.

  Upon receiving an instruction from the administrator, the IP multicast subscription group management means 5 first registers the IPv4 address 238.0.0.1 in the IPv4 multicast subscription table 51, and sets the IPv4 address 238.0.0.1 as The IP translation information holding unit 4 is instructed to register the corresponding IPv6 address in the IP address translation table 41.

  The IP translation information holding unit 4 searches the IP address translation table 41 with the IPv4 address 238.0.0.1, and if a corresponding entry is found, reports the fact to the IP multicast subscription group management unit 5. If the corresponding entry is not found, an IPv6 multicast address is acquired from the translation IP address holding means 3 and registered in the IP address translation table 41 in association with the IPv4 address 238.0.0.1. Report to the multicast subscription group management means 5. Here, since the corresponding entry is not found, the IPv6 multicast address (ff1e :: 100) is acquired from the translation IP address holding means 3 and associated with the IPv4 address 238.0.0.1 in the IP address translation table 41. It is registered and the fact is reported to the IP multicast subscription group management means 5.

  When the IP multicast subscription group management means 5 receives the report indicating that the corresponding entry has been registered from the IP translation information holding means 4, the “IGMP Membership Report indicating the subscription to the IP multicast group with the IPv4 address 238.0.0.1” “Instructs the IP transmitting / receiving means 2 to transmit a message (IGMP: Internet Group Management Protocol) to the IPv4 network 101.

  The IP transmission / reception unit 2 transmits an “IGMP Membership Report” message to the IPv4 network 101 in accordance with the instruction of the IP multicast subscription group management unit 5.

  As a result, the conversion apparatus 1a receives an IPv4 multicast packet that the IPv4 multicast server 104 broadcasts (sends) to the IPv4 network 101 with an IPv4 address of 238.0.0.1, and performs the following processing (FIG. 11). I do.

  When receiving the IPv4 multicast packet from the IPv4 network 101, the IP transmission / reception means 2 inquires of the IP multicast subscription group management means 5 whether the IPv4 end point address of the received IPv4 multicast packet has joined the multicast group.

  The IP multicast subscription group management means 5 checks whether the IPv4 end point address is registered in the IPv4 multicast subscription table 51 and reports the result (subscribed / not subscribed) to the IP transmission / reception means 2. Here, since the IPv4 address of 238.0.0.1 is registered in the IPv4 multicast subscription table 51, it is reported that it has been subscribed.

  The IP transmission / reception means 2 discards the IPv4 multicast packet when it receives a non-subscription report from the IP multicast subscription group management means 5, and when it receives a subscription report, it sends the IPv4 multicast to the IP header conversion means 6. Pass the packet. In this case, since it has received a subscribed report, the IPv4 multicast packet is transferred to the IP header converting means 6.

  When receiving the IPv4 multicast packet from the IP transmission / reception unit 2, the IP header conversion unit 6 inquires the IPv6 address corresponding to each of the IPv4 end point address and the IPv4 start point address to the IP address conversion information holding unit 4.

  The IP address translation information holding unit 4 first checks whether the IPv4 end point address is registered in the IP address translation table 41, and if it is registered, reports the corresponding IPv6 address to the IP header translation unit 6. If not registered, report that it has not been registered. Here, since the IPv4 end point address (238.0.0. 1) is registered in the IP address conversion table 41, the corresponding IPv6 address (ff1e :: 100) is reported.

  Next, the IP address translation information holding unit 4 checks whether the IPv4 start point address is registered in the IP address translation table 41, and if it is registered, reports the corresponding IPv6 address to the IP header translation unit 6. If not registered, an IPv6 unicast address is obtained from the translation IP address holding means 3 and registered in the IP address translation table 41 in association with the IPv4 start address, and then the IPv6 unicast address is reported. Here, since the IPv4 start point address (133.144.93.2) is not registered in the IP address conversion table 41, the IPv6 unicast address (1 :: 100) is acquired from the conversion IP address holding means 3, After registering in the IP address conversion table 41, the IPv6 unicast address is reported.

  When receiving an IPv6 address report corresponding to each of the IPv4 end point address and the IPv4 start point address from the IP address conversion information holding unit 4, the IP header conversion unit 6 converts the IPv4 multicast packet into the IPv6 multicast packet by IP header conversion. And instruct the IP transmission / reception means 2 to send it to the IPv6 network. In the IP header conversion, the IP header conversion means 6 converts the IPv4 end point address into an IPv6 end point address using the corresponding IPv6 address, and converts the IPv4 start point address into an IPv6 start point address using the corresponding IPv6 address. . When the report that the IPv4 end point address is not registered is received from the IP address translation information holding unit 4, the IPv4 multicast packet is discarded. Here, the IPv6 address (ff1e :: 100) corresponding to the IPv4 end point address (238.0.0.1) and the IPv6 address (1: :) corresponding to the IPv4 start point address (133.144.93.2). 100) is received from the IP address translation information holding means 4, and an IPv6 multicast packet is created from the IPv4 multicast packet by IP header translation that translates into an IPv6 end address and an IPv6 start address using the corresponding IPv6 addresses. Then, the IP transmission / reception means 2 is instructed to send the packet to the IPv6 network.

  The IP transmission / reception unit 2 transmits the IPv6 multicast packet to the IPv6 network 102 according to the instruction of the IP header conversion unit 6.

  The IPv6 multicast client 107 receives the IPv6 multicast packet by joining the IPv6 multicast group of the IPv6 end point address (ff1e :: 100) of the IPv6 multicast packet.

As described above, the IPv6 multicast client 107 can receive the IP multicast packet broadcast (transmitted) to the IPv4 network 101 by the IPv4 multicast server 104 with the IPv4 address of 238.0.0.1.

  In the above embodiment, the IPv4 multicast server 104 receives an IPv4 multicast packet broadcast (transmitted) to the IPv4 network 101 using the IPv4 address of 238.0.0.1. The same applies when the IPv4 multicast client 106 receives an IPv6 multicast packet broadcast (transmitted) to the IPv6 network 102 with the IPv6 address of ff1e :: 1. That is, the conversion device 1a receives an IPv6 multicast packet broadcast (transmitted) by the IPv6 multicast server 106 to the IPv6 network 102, creates an IPv4 multicast packet from the IPv6 multicast packet received by IP header conversion, and sends it to the IPv4 network. The IPv4 multicast client 105 receives the IPv4 multicast packet created by the conversion apparatus 1a and sent to the IPv4 network.

  In the above embodiment, the conversion apparatus 1a converts the IP header for the IPv4 multicast group instructed by the administrator. However, the conversion apparatus 1a converts the IP header for the IPv4 multicast group automatically detected by monitoring the IPv4 network. good. Similarly, an IPv6 multicast group that is automatically detected by monitoring an IPv6 network may be subjected to IP header conversion.

  In the above-described embodiment, the IPv4 end point address (238.0.0. 1) of the IPv4 multicast packet broadcast (transmitted) by the IPv4 multicast server 104 to the IPv4 network 101 is acquired from the conversion IP address holding unit 3. The case of converting to a multicast address (ff1e :: 100) has been described, but a 128-bit IPv6 address (for example, ff1e :: ffff: with a fixed pattern added above the IPv4 end point address (238.0.0.1)). 238.0.0.1) may be converted.

  In the above embodiment, the case where the conversion apparatus 1a and the IPv4 multicast server 104 are connected to the same IPv4 network 101 as shown in FIG. 9 has been described. However, as shown in FIG. 12, they are connected to different IPv4 networks. The same applies to the case where the operation is performed. In this case, the IPv4 multicast router receives an IGMP message transmitted from the translation apparatus 1a to join the IPv4 address of 238.0.0.1, the multicast routing protocol works between the IPv4 multicast routers, and the IPv4 multicast packet is IPv4. It reaches the conversion apparatus 1a from the multicast server 104. The same applies to the case where the conversion apparatus 1a and the IPv4 multicast server 104 are connected to different IPv6 networks.

  DESCRIPTION OF SYMBOLS 1a ... Conversion apparatus, 2 ... IP transmission / reception means, 3 ... IP address holding means for conversion, 4 ... IP address conversion information holding means, 5 ... IP multicast subscription group management means, 6 ... IP header conversion means, 31 ... IPv4 unicast Address table, 32 ... IPv4 multicast address table, 33 ... IPv6 unicast address table, 34 ... IPv6 multicast address table, 41 ... IP address conversion table, 51 ... IPv4 multicast subscription table, 52 ... IPv6 multicast subscription table, 101 ... IPv4 network , 102 ... IPv6 network, 104 ... IPv4 multicast server, 105 ... IPv4 multicast client, 106 ... IPv6 multicast server, 107 ... IPv6 malware Cast client.

Claims (8)

An IPv4-IPv6 multicast communication device connected to both an IPv4 network and an IPv6 network,
A transmission / reception unit for transmitting / receiving packets to / from the IPv4 network and IPv6 network;
When a multicast packet is received from the IPv4 network or the IPv6 network, a subscription group management unit that confirms whether the IPv4-IPv6 multicast communication device participates in the received multicast packet group;
An IPv4-IPv6 multicast communication apparatus comprising: an address conversion unit that converts a destination multicast address of the received multicast packet into a multicast address of a network having a different address system from that of the received network. An IPv4-IPv6 multicast communication device according to claim 1,
The IPv4-IPv6 multicast communication apparatus joins a multicast group by outputting an IGMP Membership Report message. An IPv4-IPv6 multicast communication device according to claim 2,
In addition, it has a subscription table for managing participating multicast groups,
An IPv4-IPv6 multicast communication apparatus, which refers to the subscription table and determines whether to transfer the received multicast packet to a network having a different address system from the received network. An IPv4-IPv6 multicast communication device according to claim 3,
An IPv4-IPv6 multicast communication apparatus comprising a multicast address table that holds in advance addresses used by the address translation unit for translation. A multicast communication method in an IPv4-IPv6 multicast communication device connected to both an IPv4 network and an IPv6 network,
Receiving a multicast packet from the IPv4 network or IPv6 network;
Confirming whether it participates in the group of the received multicast packets;
A multicast communication method comprising a step of converting a destination multicast address of the received multicast packet into a multicast address of a network having a different address system from the received network. The multicast communication method according to claim 5, comprising:
A multicast communication method comprising joining an multicast group by outputting an IGMP Membership Report message. The multicast communication method according to claim 6, wherein
And storing the participating multicast groups;
A multicast communication method comprising determining whether to transfer the received multicast packet to a network having a different address system from the received network based on the stored multicast group. The multicast communication method according to claim 7, comprising:
A multicast communication method comprising a step of previously holding an address used for the address translation.

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